Tire belt formation is a well known practice that involves pulling multiple cords through an extrusion die. The extruder heats elastomeric material and coats the cords traveling through the die. Cooling drums adjacent to the extruder act both to pull the cords through the die and cool the fiber reinforced material before the cutting and splicing phase of production. After traveling through the cooling drums, the fiber reinforced material is allowed to hang with some slack in order to remove some residual forces. The fiber reinforced material is then drawn onto a cutting station. The cutting station includes a strip vacuum transfer, a cutter and a belt conveyor. The strip vacuum transfer advances the fiber reinforced strip and positions it on the belt conveyor so that the cutter may cut the fiber reinforced material. The belt conveyor then indexes a predetermined distance. The strip vacuum transfer again advances the strip onto the conveyor so that the cutter again cuts it. This process results in a continuous belt of fiber reinforced material with the reinforcing cords lying at some angle typically not parallel to the central axis of the belt.
The cut sections of this material overlap one another on the belt conveyor by a predetermined distance. This overlap is generally known in the art as a splice. A uniform splice is needed to maintain proper material strength and quality. The belt conveyor is typically aligned at an angle relative to the fiber reinforced material entering the cutting station, such that after the splicing process, a continuous strip of material lays on the conveyor, comprised of fibers oriented at a predetermined angle.
Because the process involves uncured elastomeric material, handling of the material is difficult. This difficulty stems largely from the variability in width of the fiber reinforced strip. This variability manifests itself largely at the splicing portion of the process. Difficulties in aligning adjacent sheets on the belt conveyor often result in poor splices making the belt unsuitable for its intended use. These inaccuracies are often the result of inconsistent dimensioning of the material as it comes out of the extruder. Presently, to achieve good dimensional accuracy and splices, the belt making system relies heavily on the human operator that monitors the dimensional accuracy of the fiber reinforced material as it comes from the extruder and makes adjustments at various stages of the process, to ensure good splices. For instance, operation of the cutting station requires that an operator cut an initial strip of fiber reinforced material and place it on the belt conveyor, manually index the belt conveyor, cut another strip, and establish a good splice. This index distance is then stored in the cutting station hardware such that once placed in an automatic operation mode, the conveyor will advance that pre-set distance automatically after each cut and splice. Any change in the fiber reinforced material width must be continually monitored by the operator. If material width changes and adjustments are not made to the index distance, a poor splice will result. This problem was overcome in the past through extensive operator supervision. If the operator detected a change in the fiber reinforced strip width, he would place the machine in a manual mode, reestablish a good splice and then place the cutting station back in automatic mode. This required experienced operators to ensure a quality product. Also, the manual adjustments result in a loss in efficiency.
As will be appreciated, given the number of stages involved in the process and the intense focus needed to monitor all of the controls, operators must acquire a great deal of experience before becoming sufficiently proficient in operating the machine, to produce consistent quality results. As a result, during the learning process, the system may not operate at its most efficient rate.
Consequently, to improve efficiency, in terms of consistent quality product, a tire belt making system that relieves some of the burden on the human operator is desirable.